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PubMed1995

A sapecin homologue of Holotrichia diomphalia: purification, sequencing and determination of disulfide pairs.

We purified and characterized a sapecin homologue, named holotricin 1, from the hemolymph of immunized larvae of a coleopteran insect, Holotrichia diomphalia. We determined its complete amino acid sequence and three disulfide pairs. Holotricin 1 consisted of 43 amino acid residues and showed potent antibacterial activity against gram-positive bacteria, but antibacterial activity against gram-negative bacteria was not obvious.

Amino Acid Sequence↗
PubMed1994

Cloning of cDNAs for cecropins A and B, and expression of the genes in the silkworm, Bombyx mori.

cDNA clones coding cecropins A and B were isolated from a cDNA library constructed from the fat body of immunized Bombyx mori larvae. The cloned cDNAs had an open reading frame of 63 amino acids, indicating the primary translated peptides were processed to form mature cecropins of 35 amino acid residues. The homology in the coding regions of cecropins A and B was 73%. In immunized fat body, the expression of both cecropin A and B genes reached the maximal level 5 h after the injection of soluble peptidoglycan, and the high level was maintained until 9 h after immunization. The cecropin A and B genes were expressed at high levels in fat body and hemocytes, at lower but significant levels in malpighian tube, slightly in midgut, and none in silk gland.

Amino Acid Sequence↗
PubMed2002

Occurrence of GalNAcbeta1-4GlcNAc unit in N-glycan of royal jelly glycoprotein.

Elsewhere, we characterized the structure of twelve N-glycans purified from royal jelly glycoproteins (Kimura, Y. et al., Biosci. Biotechnol. Biochem., 64, 2109-2120 (2000)). Structural analysis showed that the typical high-mannose type structure (Man9-4GlcNAc2) accounts for about 72% of total N-glycans, a biantennary-type structure (GlcNAc2Man3GlcNAc2) about 8%, and a hybrid-type structure (GlcNAc1Man4GlcNAc2) about 3%. During structural analysis of minor N-glycans of royal jelly glycoproteins, we found that one had an N-acetyl-galactosaminyl residue at the non reducing end; most of such residues have been found in N-glycans of mammalian glycoproteins. By exoglycosidase digestion, methylation analysis, ion-spray (IS)-MS analysis, and 1H NMR spectroscopy, we identified the structure of the N-glycan containing GalNAc as; GlcNAc(beta)1-2Man(alpha)1-6(GalNAcbeta1 - 4GIcNAcbeta1 - 2Man(alpha)1 - 3)Manbeta1 - 4GlcNAc(beta)1-4GlcNAc. This result suggested that a beta1-4 GalNAc transferase is present in hypopharyngeal and mandibular glands of honeybees.

Animals↗
PubMedDate not supplied

Incorporation of a Calliphora arylphorin gene into the germ line of Drosophila by p-element-mediated transformation.

Two arylphorin gene clones were inserted into the transposable p-element vector Carnegie 20 and injected into Drosophila rosy- mutants. Transponed animals were selected by their red eye colour and remated. We demonstrate by hybridization experiments the stable integration of the injected genes in the germ line of Drosophila. However, the incorporated genes are not expressed.

Animals↗
PubMed2004

Mechanisms of dendritic elaboration of sensory neurons in Drosophila: insights from in vivo time lapse.

In vivo time-lapse multiphoton microscopy was used to analyze the remodeling of the dendritic arborizing (da) sensory neuron known as dorsal dendritic arborizing neuron E (ddaE) during metamorphosis. After its larval processes have been removed, the cell body of ddaE repositions itself on the body wall between 25 and 40 hr after puparium formation (APF) and begins its adult outgrowth at 40 hr APF. The scaffold of the arbor is laid down between 40 and 54 hr APF, when growth is characterized by high filopodial activity at both terminal and interstitial positions and by branch retraction along with branch establishment. Later in development, filopodial activity remains high but is confined to terminal branches, and branch retraction is no longer seen. Treatment with the insect hormone juvenile hormone (JH), a key regulator of metamorphosis, alters the shape and complexity of the adult dendritic tree in a time-dependent manner. Early treatments with juvenile hormone mimic (JHm) appear to repress extension programs and maintain retraction programs. With later JHm treatments, extension programs appear normal, but retraction programs are maintained beyond their normal time. The JH treatments show the importance of retraction programs in establishing the overall arbor shape.

Animals↗
PubMedDate not supplied

Inhibition of high voltage-activated Ca2+ currents from cultured sensory neurones by a novel insect peptide.

PMP-D2, a novel 35 amino acid peptide isolated from the brain of the locust Locusta migratoria, is localised specifically in neurosecretory cells and nerve tracts of the Pars intercerebralis. When PMP-D2 is applied onto rat sensory neurones it blocks high voltage-activated inward Ca2+ currents at concentrations ranging from 0.1 mu M to 10 mu M. The inhibitory effect of PMP-D2 is more marked on the sustained inward Ca2+ current measured at the end of 100 ms voltage step commands than on the maximum inward Ca2+ current. These results suggests that PMP-D2 may differentially inhibit the two components of the high voltage-activated inward Ca2+ currents of rat sensory neurones.

Animals↗
PubMed1996

Immunomodulatory properties of maxadilan, the vasodilator peptide from sand fly salivary gland extracts.

Sand flies are the arthropod vector of leishmaniasis and salivary gland extracts from these flies exacerbate leishmaniasis in vivo. The mechanism of exacerbation appears to be due to immunomodulatory effects of the saliva on host immune function but the active component is unknown. The following studies reveal that maxadilan, the vasodilatory peptide present in sand fly salivary gland extracts, has immunomodulatory properties. To examine the effect of maxadilan on T cell proliferation, the peptide was added to murine spleen cells stimulated with either concanavalin A or plate-bound anti-T cell receptor antibody. Inhibition of proliferation was noted in a dose-dependent manner for both sets of experiments (P < 0.05). To examine the effect of maxadilan on alloantigen presentation, the peptide was added to mixed lymphocyte and mixed epidermal cell lymphocyte reactions. Inhibition of proliferation was found in these culture systems. Maxadilan also inhibited the delayed-type hypersensitivity reaction in mice (P < 0.05). These observations suggest a role for maxadilan in the pathogenesis of leishmaniasis since the peptide may inhibit the immune response at the site of parasite inoculation, allowing the infection to proceed.

Adjuvants, Immunologic↗
PubMed1992

Structural requirements for transport of preprocecropinA and related presecretory proteins into mammalian microsomes.

The presecretory protein preprocecropinA (which comprises 64 amino acid residues) as well as a synthetic hybrid between preprocecropinA and dihydrofolate reductase (which comprises 252 amino acid residues) are processed by and transported into mammalian microsomes. Transport of both precursor proteins can take place cotranslationally, i.e. with the aid of ribosome and signal recognition particle, or posttranslationally, i.e. independently of these ribonucleoparticles (RNPs). We investigated the role of the precursor structure with respect to competence for RNP-independent transport by constructing deletion mutants and hybrid proteins. The results demonstrate that the signal peptide is essential for RNP-independent transport. Furthermore, the signal peptide is sufficient for translocation of preprocecropinA derivatives up to 85 amino acid residues in size. However, the conformation of the precursor protein is decisive in the case of larger hybrid proteins.

Amino Acid Sequence↗
PubMed1992

Amino acid sequence of Sp23, a structural protein of the spermatophore of the mealworm beetle, Tenebrio molitor.

In this paper we present the amino acid sequence of Sp23, a structural protein of the spermatophore of the mealworm beetle (Tenebrio molitor). This is the first report of the primary structure of a spermatophorin. The protein is rich in proline (24%), relatively rich in tyrosine (9%) and glutamine (10%), and does not contain sulfur-containing amino acids. In the carboxyl-terminal half of the protein a peptide motif is repeated which is similar to a repetitive motif in a group of dipteran chorion proteins.

Amino Acid Sequence↗
PubMed1991

A highly repetitive, mariner-like element in the genome of Hyalophora cecropia.

A highly repetitive DNA element, homologous to the mariner transposon of Drosophila mauritiana was found in the intron of the gene for cecropin A, an antibacterial peptide from the Cecropia moth. The mariner-like elements (MLE) represent a homogeneous population with a copy number of about 1000/genome. Sequencing analysis showed it to be 1255 base pairs long, including 38-base pair terminal inverted repeats. The MLE contains a defective reading frame. Nevertheless, the putative product is clearly homologous to the predicted translation product encoded by mariner. In consonance is also the fact that the inverted repeats are highly conserved between the two elements and that the overall DNA homology is 48%. Since the mariner element is present in several Drosophila species closely related to Drosophila melanogaster and since MLE is present in the lepidopteran Cecropia, a route of horizontal transfer is indicated rather than vertical transmission from a common ancestor. This suggests the possible use of mariner for the construction of an interspecies vector.

Amino Acid Sequence↗
PubMed1991

The cecropin locus. Cloning and expression of a gene cluster encoding three antibacterial peptides in Hyalophora cecropia.

Cecropins A, B, and D are antibacterial peptides of 35-37 amino acids that are synthesized in pupae of the Cecropia moth (Hyalophora cecropia) as a response to a bacterial infection. cDNA cloning has shown that the cecropins are made as preproproteins that are processed in four steps to the mature peptides. We have now cloned the genes for preprocecropins A and D, data that together with earlier work on the B gene has made it possible to deduce the arrangement of the cecropin locus. The genes for the three cecropins are organized in a large cluster spanning 20 kilobases of DNA and for each gene there is one copy/haploid genome. The size of the cluster is in part due to long distances between the genes and to the presence of insertion elements in the introns of the A and D genes. The cecropin genes are not expressed in parallel. Transcripts for cecropins A and B appear within 2 h after injection of live bacteria, they reach a maximum after 48 h, and they are continuously expressed at this level for several days. The D gene has a delayed pattern of expression where transcripts appear within 48-96 h and reach a maximum after 144 h. In consonance is also the production of the mature cecropins A, B, and D where the active cecropins A and B are detected in the hemolymph within 10-24 h while the D form is not detected until 48 h post infection. Control injections with sterile saline produced only a weak induction of the cecropin genes.

Amino Acid Sequence↗
PubMed1992

Isolation, characterization, and cDNA sequence of two fatty acid-binding proteins from the midgut of Manduca sexta larvae.

Two abundant fatty acid-binding proteins (MFB1 and MFB2) were isolated from the midgut cytosol of larval Manduca sexta. As isolated, MFB1 and MFB2 were found to contain bound fatty acids in a 1:1 molar stoichiometric ratio. Immunological screening demonstrated that MFB1 and MFB2 were restricted to the midgut in a gradient distribution, with MFB1 more concentrated in the anterior two-thirds of the midgut and MFB2 more concentrated in the posterior two-thirds of the midgut. MFB1 exchanged fatty acid more readily than did MFB2. MFB1 was about 2% and MFB2 about 12% of the cytosolic protein in the midgut. cDNA clones for MFB1 and MFB2 both encode proteins of 131 amino acids that are rich in lysine and acidic residues. Analysis of the amino acid sequence alignment of the MFBs with six mammalian fatty acid-binding proteins revealed a number of shared features: 9 conserved glycines, presumably important in turns of the beta-strands; a basic amino acid in a position corresponding to the residue reported to participate in binding the carboxyl group of the fatty acid (Arg in MFB1 and Lys in MFB2); and conservation of many of the residues important in binding the aliphatic portion of the fatty acid.

Amino Acid Sequence↗
PubMed1992

Maxadilan. Cloning and functional expression of the gene encoding this potent vasodilator peptide.

Maxadilan is a potent vasodilator peptide released into the skin when the sand fly Lutzomyia longipalpis, an important vector of leishmania, probes for a blood meal. As several lines of evidence suggest that this peptide may play a critical role in the enhancement of leishmania infectivity attributed to sand fly saliva, the peptide has been proposed as a candidate antigen for a leishmanial vaccine. Although maxadilan is the most potent vasodilator peptide known and shares several properties with calcitonin gene-related peptide (CGRP), studies of its structure, physiological effects, and biological roles have been limited by the miniscule quantities available. Here we report the isolation of cDNA and genomic DNA clones that encode maxadilan. The predicted translation product shows no significant homology with any previously isolated proteins. The coding DNA has been expressed in Escherichia coli and the purified recombinant peptide is biologically active with a specific activity comparable to the natural peptide. Recombinant maxadilan will be useful in studies of vascular biology and could lead to novel therapeutic and prophylactic agents.

Amino Acid Sequence↗